And that worked for many decades, until the eco-wussies decided that the seals didn't have enough room on the entire rest of the California coast, and decided to banish the humans from enjoying this one protected spot.
My daughter, then about 10, was screamed at by the eco weanies around 2005 for daring to walk across that beach, even after the rope was ordered down and people were using it again.
This has nothing to do with the ability of seals to breed adequately. It has everything to do with activists and bureaucrats lording their power over everybody else.